This relates generally to electronic devices with displays, and, more particularly, to systems having displays and tunable lenses.
Display systems may be used to display virtual reality content. For example, a system may have a display and a pair of tunable lenses aligned with the left and right eyes of a user. The user may view images on the display through the tunable lenses. To create an illusion of depth in the displayed images, a series of different images may be displayed as the lenses are sequentially tuned to different focal lengths. For example, distant portions of a scene may be displayed when the focal length is tuned to a long focal length setting and foreground portions of a scene may be displayed when the focal length is tuned to a short focal length setting. By adjusting focus and image content in this way, vergence-accomodation conflicts can be reduced.
Challenges may arise when using this type of device to display three-dimensional images. If care is not taken, the tunable lenses may introduce lens distortion. The lens distortion may make it difficult or impossible for the user to view satisfactory images.